Submersible pump



Jan. 26, 1954 BERGH 2,667,128

SUBMERSIBLE PUMP Filed Dec. 13, 1950 3 Sheets-Sheet 2 68 INVE NTORCHARLES J. BERGH I ATTORNEYS Jam 1954 c. J. BERGH 2,667,128

SUBMERSIBLE PUMP Filed Dec. 15, 1950 3 Sheets-Sheet 3 I MIMJMUHTM ATTORNEYS Patented Jan. 26, 1954 SUBMERSIBLE PUMP Charles J Bergh,Vandalia, Ohio, assignor to The Dayton Pump & Manufacturing Company,Dayton, Ohio, a corporation of Ohio Application December 13, 1950,Serial N 0. 200,645

1 Claim.

This invention relates to submersible pumps, and particularly tomultistage submersible pumps having an electric drive motor integrallymounted therewith.

Pumps of the type generally referred to above are known in the art, andone having the same general construction as the one with which thisapplication is concerned is illustrated in my copending application,Serial No. 176,496, filed July 28, 1950, now Patent No. 2,648,286, ofAugust 11, 1953.

Submersible pumps, as illustrated in the present application and thecopending application referred to, are adapted for being inserted in awell casing or the like as a unit to be supported on the down pipethrough which the fluid pump from the well is discharged. The pump unitis supported entirely on the down pipe and has no connection with thewell casing.

In the pump construction illustrated in application Serial No. 176,496,I illustrated a multistage pump in which the housing of the pump and thevarious parts associated therewith, such as the end members for thehousing, were integrally connected together as by soldering or brazing.This construction I found to be satisfactory when all the pump partsfall within predetermined close limits of size, and when it isunnecessary to service the pump. However, should the manufacturingtolerances on the various parts of the pump exceed predetermined limits,then that type of construction precludes the easy tearing down of thepump in order to replace or modify the defective parts.

Also, should it become necessary to service the pump due to wear orbreakage of any of the parts, the integral connection between the pumpcasing proper and the end closures thereof makes it difficult toaccomplish the dismantling of the pump with any ease, and usually itbecomes necessary to provide new casing parts.

Inasmuch as the pump unit is supported on the down pipe in the well, theelectric drive motor integral with the unit is on the lower end thereof,and diiiiculty has been encountered in making electrical connections tothe motor in such a manner that the electric leads and the motor are atall times sealed against leakage and are so arranged that the cableleading to the motor or the motor itself can readily be independentlyreplaced should it become necessary.

A pump and motor of the type referred to are positioned in a wellgenerally completely below the surface of the liquid level in the well,and there is thus always a certain static pressure standing about thepump unit. This leads to certain complications in connection with thelubrication of the bearings supporting the rotating parts of the pumpand motor.

With the motor, relatively simple and wellknown practices can befollowed in order to seal the bearings and maintain them lubricated, as,for example, by the use of ordinary shaft seals and permanentlylubricated anti-friction bearings. In the case of the pump proper,however, the problem is somewhat more difficult because fluid flowsdirectly through the pump and at an ever increasing pressure toward thedischarge end of the pump, and satisfactory shaft seals andsatisfactorily sealed bearings are not available for withstanding thesepressures and the erosion of the moving fluid.

It has been attempted to provide pressure lubricating means for thebearings of the pump so that the pressure on the lubricant willcounterbalance the water pressure pressing on the bearings from theoutside. This scheme, however, is not satisfactory because not only doesthe pressure on the fluid in the pump vary between the inlet and outlet,but it will also vary from time to time due to changes in water level inthe well, and it becomes virtually impossible to balance the lubricantpressure against the fluid pressure. Further, such pumps are often usedwhere it is desired for the delivered water to be pure and nocontamination by oil or grease can be tolerated.

Having the foregoing in mind, the principal object of the presentinvention is to provide a multistage submersible pump having an electricdrive motor which overcomes the difficulties referred to above.

A particular object is the provision of a multistage pump which canreadily be dismantled at any time for servicing.

Another particular object is the provision of an arrangement forsupplying power to the electric drive motor for the pump which does notplace any physical load on the lead-in cable and wherein the lead-incable can readily be replaced at any time.

A further object is a provision of a lead-in arrangement for supplyingpower to the electric drive motor for the pump and in which there is noleakage of fluid about the cable at any point.

It is also an object to provide an improved journaling arrangement forthe rotatable parts of the pump which eliminates the need for anyspecial lubricating arrangements for the bearings. .A still furtherobject is the provision of an arrangement whereby the pumped fluid inthe Qli lp serves to lubricate the pump impellers and to \rithstand endthrusts exerted on the impellers.

These and other objects and advantages will become more apparent uponreference to the following description taken in connection with theaccompanying drawings, in which:

Figure l is a side elevational view of a pumping unit according to myinvention;

Figure 2 is a vertical section through the pump proper drawn at asomewhat enlarged scale than is Figure 1;

Figure 3 is a transverse section indicated by line 3-3 on Figure 2;

Figure 4 is a transverse section indicated by line a s on Figure 2;

Figure 5 is a plan view which may be indicated by line 5-5 on Figure 2;

Figure 6 is a view looking down on top of an impeller housing;

Figure 7 is a vertical section taken through the impeller housing and isindicated by line "2-? on Figure 6;

Figure 8 is a view looking down on top of one of the impellers of thepump;

Figure 9 is a vertical section taken through the impeller and isindicated by line 9-5 on Fig ure 8;

Figure 10 is a side elevational view of a plug arrangement for makingelectrical connections with the drive motor of the unit;

Figure 11 is an end view of the plug looking in from the right side ofFigure 10; and

Figure 12 is an enlarged sectional view taken through the pump showingthe physical rela tionship of the impellers and impeller housings.

Referring to the drawings somewhat more in detail, Figure 1 shows anelevational view of a pumping unit constructed according to myinvention. This pumping unit comprises an elongated electric drive motorIn at the lower end, the pumping unit proper indicated at I2, and a downpipe M which is threaded into the upper end of the pump and supports theentire pumping unit inside the well.

She construction of the pump will become evident on reference to theenlarged sectional view Figure 2. In Figure 2 it will be noted that thepump comprises an outer cylindrical housing member or casing member 66which is internally threaded at its lower end, as at E8, to receive thethreaded part of the suction section 28 of the pump. The suction section23 has an annular flange 22, seal between the end of casing member l6and flange 22 preventing any leakage into or out of the pump casing.

The suction section 28 is provided with openings 26 through which thefluid to be pumped enters the casing. The lower end of suction section2G is provided with flange means through which the bolts or cap screws28 pass to engage the frame of the motor ii] for retaining it inassembled relation with the pump.

Within casing member 16 are stacked a plurality of annular members 39which are referred to as impeller housings. These annular members havean axially extending peripheral portion for engagement with thecorresponding portion of the next housing member, and these portions areshouldered top and bottom, as at 32, to provide for accurate axialalignment of the several parts within the casing of the pump.

Resting on the uppermost of the impeller and a gasket 26 provides ahousings 39 is an upper bearing section member 34 which has radial ribparts 38 that support the central hub part 33 adapted for receiving thecove bearing G9.

On top of upper bearing section 3 is a discharge section 22. Dischargemember 43 has its upper end internally threaded, as at M, for receivingthe down pipe 54 by which the entire pumping unit is suspended in thewell and through which pipe the entire discharge of the pump isconducted to its place of use.

The casing member it extends beyond the outwardly flanged lower end ofdischarge section i2 and is internally threaded, as at 48, for receivingthe externally threaded annular clamping ring 38. A gasket 5e sealsbetween the ring and the discharge section, and together with gasket 24,provides complete sealing means for the pump casing, so that when it isassembled it is as fluid tight as if the parts were brazed or solderedtogether. At the same time, the threaded end parts of the casing memberprovide means whereby the pump can readily be dismantled at any time forservicing.

The output shaft of drive motor [9 is indicated at 52, and it has atongue and slot arrangement with pump shaft 54 that has its lower endjournaled in bearing 56 and suction section 20 and its upper endjournaled in bearing 40. Shaft 5 is shouldered at 58 and has mountedthereon above the shoulder a plurality of impellers 60 that are clampedtogether in rigid relation with the shaft by clamping nuts G2 adjacentthe upper end of the shaft.

Each impeller is constructed in a substantially conventional manner, asindicated in Figures 8 and 9, and comprises a back plate 62, a frontplate E i, a hub 65, an annular inlet opening 68, and the vanes it thatdirect the fluid from the peripheral openings l2. Each annular inletopening 58 of the impellers is formed by a cylindrical projection M, andwhich projection is journaled relative to the central aperture of theadjacent impeller housing member 38 by a bearing 76.

Turning for the moment to the impeller housing, a typical one of theseis illustrated in Figures 5 and 7, wherein the housing will be seen tocomprise a fiat disk part 13 having the collector vanes 92] dependenttherefrom that receive the fluid discharge from the periphery of theimpeller beneath the housing and direct it inwardly to the centralaperture of the said housing into which extends the annular flange T4 ofthe impeller immediately above. The collector vanes 88 in this mannerserve to minimize turbulence within the pump and also serve to convert asubstantial amount of the velocity head of the fluid being pumped intopressure head at the inlet of the next following impeller.

In order to eliminate the need for lubricating the several bearingsreferred to at 40, 5G, and 16, it is preferred to form these bearings ofgraphite, or of some composition bearing sumcient graphite to providelubrication for the pump shaft and the impellers. Such a material haslong life, and is not subject to corrosion by the fluid being pumped.

The power supply to the electric drive motor E0 is brought through by anelectric cable which usually extends into the well beside the down pipe.This cable is so arranged that it assumes no physical load, but merelyhangs loosely within the well casing. As illustrated, electric cable 90is composed of whatever number of wires are required, in this casethree, Which are placed Within a waterproof and preferably semi-rigidconduit. This conduit is received in a bearing in discharge section 42to one side of the threaded bore which receives the end of down pipe I4,and there is a resilient rubber sleeve 92 in the bore that surrounds theend of the conduit.

A gland 94 is threaded into the said bore and serves to compress therubber-like sleeve so that it is pressed around the conduit and providesa water-tight seal. I have found a number of water resistant syntheticrubbers to be suitable for this purpose, and that a resilience of thirtyto forty durometer gives the sleeve the desired characteristics when itis deformed by tightening of the gland.

The said bore opens into a cavity 96 in the discharge section 42 thatcommunicates with the grooves or notches 98 that are formed in the upperbearing member 34, and in the impeller housing members 30. These notchesare lined up vertically when the pump is assembled and form a closedchannel through which the lead-in wires extend.

This channel is so formed in its lower end to communicate with a cavityI09 in suction section 20, and which cavity has an aperture I02 adaptedfor being closed by cover plate I04. Within the cavity the wiresterminate, and the separable connectors I06 which have parts connectedto relatively short leads I08 that lead to a plug III) that extendsthrough the lower surface of the suction section 20 for connection withthe leads of the motor I0.

To provide a good seal to make a permanent installation of leads I08,they preferably have formed therearound a mastic or wax or othersuitable waterproof sealing substance, as indicated at II2. Also, theplug He is surrounded by the rubber-like O-ring H4 so that there is aseal between the motor and the suction section 20 about the said plug.

A typical plug of this nature is illustrated in Figures 10 and 11,wherein it will be seen to be a substantially conventional male electricfitting which will connect with a corresponding female fitting mountedin the motor Ill. The arrangement is such that the cable can be replacedat any time merely by openingthe separable connectors I06 havingsuitable connectors, or the motor can be removed for replacement Orrepair without interfering with the cable. This serviceability of theelectric components of the pumping unit, together with the bearingsdescribed which do not require lubrication, and the separable casingparts for the pump proper make the entire unit quite easy to maintain ingood working order without the necessity of having to cut the casing ofthe cable to effect repairs.

It will be observed that as many pumping stages as desired could bebuilt into the pump merely by lengthening the casing 56 and the shaft 54of the pump and adding the required number of impellers and impellerhousings. Since the back or top of each impeller forms the bottom of thepassage leading to the next impeller above, any ordinary number ofstages in the pump will still produce a relatively compact unit.

A still further feature or" my invention is the manner in which thefluid being pumped is utilized for lubricating the impellers and forassisting in withstanding the end thrusts exerted thereon. This featureis brought out in Figure 12 which is an enlarged view showing two of thepump impellers and the impeller housing adjacent thereto.

In this view it will be noted that there is a space, as at I20, betweeneach face of each impeller and the adjacent face of the impellerhousing. The space I28 above each impeller is the space between the backface of the impeller and the lowermost surface of the guide vanesindependent of the impeller housing next above the said impeller. Thespace I29 beneath each impeller is substantially continuous from aboutthe cylindrical projection I4 of the said impeller to its periphery.

It will be noted that the front face of each impeller and the uppersurface of the impeller housing directly therebeneath are parallel. Thedescribed arrangement is availed of to provide lubrication for bothfaces of the impeller by adjusting the axial dimension of the space sothat a capillary action takes place and causes fluid being pumped by theimpeller to form a film on each side of the impeller.

It will be noted that the film standing across the lower face of theimpeller is quite effective for lubrication purposes and also serves toassist in cushioning the impeller assembly against end thrusts. Theseend thrusts will, of course, be exerted generally downwardly and thecushioning film which I provide by this capillary action greatly assistsin giving the pumping unit long life and quiet and eificient operation.

The sustaining of the axial thrusts on the impeller assembly by thecapillary film referred to, together with the sustaining of radialthrusts on the impeller assembly by the bearing rings I6 serves tomaintain the unit in efiicient and balanced operation for a long periodof time with a minimum amount of service.

The actual dimensions of the space I20 may vary considerably with thereferred to action being obtained, but I have found that a dimension ofabout one thirty-second of an inch is most practical because it can beobtained quite readily by forming the impellers and impeller housing toordinary manufacturing tolerances and is ample for providing asubstantial film between the impellers and impeller housing, without atthe same time representing any substantial amount of lost space withinthe pumping unit.

It will be understood that this invention is susceptible to modificationin order to adapt it to different usages and conditions, and,accordingly, it is desired to comprehend such modifications within thisinvention as may fall within the scope of the appended claim.

I claim:

In a submersible pump of the type described: a cylindrical casing, adischarge section in the upper end of said casing and a suction sectionin the lower end of said casing, a plurality of pumping units in stackedrelation in said casing between said sections, each said unit comprisinga centrifugal impeller having an inlet opening in its lower wall and acircular flange projecting downwardly about said opening and an impellerhousing comprising a single disk-like wall having a central aperture forreceiving said projecting flange, and having a peripheral rib upstandingabout the periphery of said impeller, a bearing ring between said flangeand the wall of said aperture to journal said flange therein and tosustain radial thrusts on said impeller, each impeller housing havingarcuate vanes depending from its underneath surface and forming channelmeans with the back of the impeller next beneath for directing the fluidbeing 7 pumped into the inlet or" the associated impeller, the lowerface of said impeller being parallel to and closely spaced from theupper face of the impeller housing next beneath, whereby a film of thepumped liquid is maintained therebetween by capillary action forcushioning and lubricatin purposes, the upper face of said impellerbeing' closely spaced from the lowermost surfaces of said vanes wherebya film or" the pumped fluid is maintained therebetween by capillaryaction for purposes of lubrication.

CHARLES J. BERGH.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,387,660 Ostenberg Aug. 16, 1921 Number Number Name DateDixon May 27, 1924 Arutunoff Apr. 1, 1941 Arutunofi Jan. 20, 1942 HowardJan. 9, 1945 Blom July 8, 1947 Wislicenus Nov. 4, 1947 Hoover Nov. 11,1947 FOREIGN PATENTS Country Date Great Britain 1885 Australia Mar. 14,1940 Great Britain Jan. 17, 1939

